The present invention relates generally to detection systems which combine signals from several sensors, and more specifically to an integrated multi-sensor system which provides the detection, location and identification of targets by comparing data from several sensor subsystems.
In recent years, interest has increased in developing "integrated" or "fused" sensor systems. Integrated sensor systems are systems consisting of multiple sensors of the same or differing types whose outputs are integrated or fused to provide an estimate of the total environment sensed by the sensors.
Single sensor systems, such as radar tracking systems, commonly compare target echo return signals received with a pre-determined expected set of hypothetical signal parameters to generate a ranking value of the identity to the target. For example, satellites present different target cross-sections and trajectories than those of re-entry vehicles. Therefore, since certain targets produce return signals with expected characteristics, a routine practice of single sensor radar systems includes assigning identifies and probabilities to actual target echo return signals.
It is generally believed that the combination of signals and/or data from several sensors ("fused", or "integrated" sensor systems) will provide better estimates of the environments sensed by these sensors than those provided by any individual sensor. The task of providing such a multi-sensor system is alleviated, to some degree, by the following U.S. patents, which are incorporated herein by reference:
U.S. Pat. No. 4,025,920 issued to H. Reitboech et al;
U.S. Pat. No. 3,913,099 issued to D. Wehner et al;
U.S. Pat. No. 3,936,826 issued to J. Hoffman;
U.S. Pat. No. 4,400,700 issued to O. Rittenbach;
U.S. Pat. No. 4,389,647 issued to M. Fanuele et al; and
U.S. Pat. No. 4,241,350 issued to M. Uffelman.
U.S. Pat. No. 4,025,920 discloses a radar identification system for identifying radar signals from selected parameters so that countermeasures may be initiated. The signals are evaluated by a matrix which includes a pattern of adaptive memory elements. U.S. Pat. No. 3,913,009 discloses an automatic digitally controlled apparatus for improving target recognition. U.S. Pat. No. 3,936,826 discloses a detection system for evaluating received parameters from an object in which the parameters are measured and compared with standard parameters.
The Rittenbach, Uffelman, and Fanuele et al references each disclose target recognition systems with multiple processing channels. While each of the references cited above are satisfactory as single sensor systems, there remains the need for a multi-sensor system which derives target information from the signals of a plurality of sensors. The present invention is intended to satisfy that need.